Method and A Device for Sequencing the ZC Sequences of the Random Access Channel

ABSTRACT

The present invention discloses a method and a device for sequencing the ZC sequences of the random access channel. The method for sequencing the ZC sequences includes the following steps: Step  202,  ZC sequences are divided into a plurality of groups according to the cubic metrics of the ZC sequences; Step  204,  the ZC sequences are sequenced, according to the maximum cyclic shift supported by the ZC sequences under a high speed circumstance, within each group to form a plurality of sub-groups; and Step  206,  the ZC sequences within each of the plurality of sub-groups are sequenced according to the cubic metrics of the ZC sequences, wherein, the adjacent sub-groups in the same group are sequenced in different orders, while the sub-groups at the boundary of the two adjacent groups are sequenced in the same order. Thereby, the sequences could be assigned according to the CMs, and the sequence fragments could be collected for use.

FIELD OF THE INVENTION

The present invention relates to communication field, in particular to amethod and a device for sequencing the ZC sequences of the random accesschannel.

BACKGROUND OF THE INVENTION

In Long Term Evolution (LTE for short) system, cyclic shift sequences ofZadoff-Chu (ZC for short) sequences are used as preambles by the RandomAccess Channel (RACH for short). These cyclic shift sequences are alsoreferred to as Zero Correlation Zone (ZCZ for short) sequences.

In practical systems, after a mobile phone is powered on, firstly,downlink synchronization is first performed, and then the detection ofthe Broadcast Channel (BCH for short) is initiated. A base stationinforms, via the BCH channel, the mobile phone the index and the steplength of the cyclic shift of the first ZC sequence available for theRACH of the current cell. According to the index, the mobile phone makesuse of certain mapping rule to calculate the serial number of thecorresponding ZC sequence, and then, generates usable ZCZ sequencesaccording to the step length of the cyclic shift and a certain “cyclicshift limitation rule”. If the number of the ZCZ sequences is smallerthan a certain threshold P, the mobile phone automatically incrementsthe sequence index, and continuously generates the ZCZ sequences usingthe next ZC sequence, until the total number of the ZCZ sequences islarger than or equal to P. Finally, the mobile phone randomly selectsone sequence from all the generated usable ZCZ sequences as a preambleto be sent.

In a high speed circumstance, the frequency offset caused by DopplerEffect will generate, during the process of the preamble detection, acorrelation peak alias, which will lead to a timing offset and a falsedetection. This problem is settled in LTE system through limiting theuse of some cyclic shifts according to a certain rule, which is thementioned “cyclic shift limitation rule”. Meanwhile, the cyclic shiftlimitation rule also limits the maximum cyclic shift N_(CS)corresponding to each ZC sequence, and this maximum cyclic shiftdirectly determines the maximum cell radius supported by each ZCsequence. Supposing that the distance between the correlation peak andthe correlation peak alias thereof is du, the relation between themaximum cyclic shift N_(CS) and du is:

N _(CS)=min(du, N _(ZC)−2·du)   (1)

wherein, N_(ZC) is the length of a ZC sequence, du can be calculated bythe following formula:

$\begin{matrix}{{du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}}\end{matrix} \right.} & (2)\end{matrix}$

wherein, u is the serial number of the ZC sequence, and m is the minimumpositive integer which makes

$\frac{{m \cdot N_{ZC}} - 1}{u}$

a positive integer.

The mapping process between the indices and the serial numbers of the ZCsequences is actually the process of re-sequencing the ZC sequences. Atpresent, there are mainly two sequencing methods: one is to sequenceaccording to the cubic metric (CM for short, it is a standard formeasuring the Peak-to-Average Power Ratio of the emitted data, thelarger the CM is, the higher the Peak-to-Average Power Ratio is) of theZC sequences, and the other is to sequence according to the maximum cellradius supported by each ZC sequence. The first method is advantageousin that network planning can be conveniently performed according to theCM of a root sequence so as to assign the sequences with smaller CMs tothe cells with larger radius, and the sequences with close CMs to thesame cell. Its shortcoming lies in that sequence fragments will begenerated, which will cause the waste of the sequences. In other words,during the process of generating the ZCZ sequences with the continuousincrementation of the sequence index, if the maximum cell radiussupported by a ZC sequence is smaller than the radius of the currentcell, this sequence neither could be used by the current cell, nor itcould be used by other cells having radiuses smaller than the maximumcell radius supported by this ZC sequence (this is because that theindex is continuously incremental, as shown in FIG. 1). The secondmethod is advantageous in avoiding the generation of the sequencefragments, that is disadvantageous in that the CMs of the ZC sequencesassigned to a cell differs greatly from each other so that sequenceplanning can not be performed according to the CM.

SUMMARY OF THE INVENTION

In view of the above mentioned one or more problem, the presentinvention provides a method and a device for sequencing the ZC sequencesof the random access channel.

The method for sequencing the ZC sequences of the random access channelaccording to the embodiments of the present invention comprises thefollowing steps: Step 202, Nq ZC sequences are divided into a pluralityof groups according to the cubic metrics of the ZC sequences; Step 204,the ZC sequences are sequenced, according to the maximum cyclic shiftsupported by the ZC sequences under a high speed circumstance, withineach group to form a plurality of sub-groups; and Step 206, the ZCsequences are sequenced within each of the plurality of sub-groupsaccording to the cubic metrics of the ZC sequences, wherein, theadjacent sub-groups in the same group are sequenced in different orders,while the sub-groups at the boundary of the two adjacent groups aresequenced in the same order.

Wherein, in Step 202, Nq ZC sequences are divided into G groups,wherein, 1≦G≦Nq, the relation between the serial number of each of theplurality of groups and the cubic metrics of the ZC sequences in each ofthe plurality of groups is: the cubic metrics of the ZC sequences inGroup i are smaller than the cubic metrics of the ZC sequences in Groupi+1, or the cubic metrics of the ZC sequences in Group i are larger thanthe cubic metrics of the ZC sequences in Group i+1. Specifically, Nq ZCsequences may be divided into two groups according to the cubic metricsof Quadrature Phase Shift Keying.

Wherein, in Step 202, firstly, Nq ZC sequences are sequenced, in thedecreasing order or in the increasing order, according to the cubicmetrics of the ZC sequences, and then, the sequencing result is dividedinto a plurality of groups according to one or more cyclic shiftthresholds.

Wherein, the sequencing process in Step 204 may be performed in theincreasing order or in the decreasing order, and the adjacent groups aresequenced in different orders.

Wherein, the sequencing process in Step 204 needs to be performedaccording to a certain granularity. The granularity of the cyclic shiftof Group g is P^(g)={P₁ ^(g), P₂ ^(g), . . . , P_(s) ^(g)}, and P_(i)^(g)<P_(i+1) ^(g), thus, (1) the sequencing performed in the increasingorder means: when 1<i<s, the maximum cyclic shift supported by eachsequence in Sub-group i under the high speed circumstance is smallerthan P_(i+1) ^(g), and larger than or equal to P_(i) ^(g), when i=1, themaximum cyclic shift supported by each sequence in Sub-group i under thehigh speed circumstance is smaller than P₁ ^(g), when i=s, the maximumcyclic shift supported by each sequence in Sub-group i under the highspeed circumstance is larger than or equal to P_(s) ^(g); (2) thesequencing performed in the decreasing order means: when 1<i<s, themaximum cyclic shift supported by each sequence in Sub-group i under thehigh speed circumstance is smaller than P_(s−i+2) ^(g) and larger thanor equal to P_(s−i+1) ^(g), when i=1, the maximum cyclic shift supportedby each sequence in Sub-group i under the high speed circumstance islarger than or equal to P_(s) ^(g), when i=s, the maximum cyclic shiftsupported by each sequence in Sub-group i under the high speedcircumstance is smaller than P_(i) ^(g).

Wherein, the maximum cyclic shift N_(CS)=min(du, N_(ZC)−2·du), wherein,du is the distance between a correlation peak and a correlation peakalias thereof, and N_(ZC) is the length of the ZC sequence. The distancebetween the correlation peak and the correlation peak alias thereof is

${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}},}\end{matrix} \right.$

wherein, u is the serial number of the ZC sequence, and m is the minimumpositive integer which makes

$\frac{{m \cdot N_{ZC}} - 1}{u}$

a positive integer.

The device for sequencing the ZC sequences of the random access channelaccording to the embodiments of the present invention comprises: a firstgroup dividing unit, configured to divide Nq ZC sequences into aplurality of groups according to the cubic metrics of the ZC sequencesof the random access channel; a to second group dividing unit,configured to sequence the ZC sequences within each group to form aplurality of sub-groups, according to the maximum cyclic shift supportedby the ZC sequences under a high speed circumstance; and a sequencingunit, configured to sequence the ZC sequences in each of the pluralityof sub-groups according to the cubic metrics of the ZC sequences,wherein, the adjacent sub-groups in the same group are sequenced indifferent orders, while the sub-groups at the boundary of the twoadjacent groups are sequenced in the same order.

Wherein, the first group dividing unit divides Nq ZC sequences into Ggroups, wherein, 1≦G≦Nq, the relation between the serial number of eachof the plurality of groups and the cubic metrics of the ZC sequences ineach of the plurality of group is: the cubic metrics of the ZC sequencesin Group i are smaller than the cubic metrics of the ZC sequences inGroup i+1, or the cubic metrics of the ZC sequences in Group i arelarger than the cubic metrics of the ZC sequences in Group i+1.Specifically, the first group dividing unit divides the Nq ZC sequencesinto two groups using the cubic metrics of Quadrature Phase Shift Keyingas a threshold.

Wherein, the second group dividing unit divides the ZC sequences in eachsub-group into a plurality of sub-groups according to one of thefollowing principles: the maximum cyclic shift supported by the ZCsequences in Sub-group i under the high speed circumstance is smallerthan the maximum cyclic shift supported by the ZC sequences in Sub-groupi+1 under the high speed circumstance, the maximum cyclic shiftsupported by the ZC sequences in Sub-group i under the high speedcircumstance is larger than the maximum cyclic shift supported by the ZCsequences in Sub-group i+1 under the high speed circumstance, wherein,the second group dividing unit applies different principles to thesub-groups in adjacent groups.

Wherein, the sequencing process of the second group dividing unit may beperformed in the increasing order or in the decreasing order, and theadjacent groups should be sequenced in different orders.

Wherein, the sequencing process of the second group dividing unit needsto be performed according to a certain granularity. The granularity ofthe cyclic shift of Group g is P^(g)={P₁ ^(g), P₂ ^(g), . . . , P_(s)^(g)}, and P_(i) ^(g)<P_(i+1) ^(g), thus, (1) performing the sequencingin the increasing order means: when 1<i<s, the maximum cyclic shiftsupported by each sequence in Sub-group i under the high speedcircumstance is smaller than P_(i+1) ^(g), and larger than or equal toP_(i) ^(g), when i=1, the maximum cyclic shift supported by eachsequence in Sub-group i under the high speed circumstance is smallerthan P₁ ^(g), when i=s, the maximum cyclic shift supported by eachsequence in Sub-group i under the high speed circumstance is larger thanor equal to P_(s) ^(g); (2) performing the sequencing in the decreasingorder means: when 1<i<s, the maximum cyclic shift supported by eachsequence in Sub-group i under the high speed circumstance is smallerthan P^(s−i+2) ^(g), and larger than or equal to P_(s−i+1) ^(g), wheni=1, the maximum cyclic shift supported by each sequence in Sub-group iunder the high speed circumstance is larger than or equal to P_(s) ^(g),when i=s, the maximum cyclic shift supported by each sequence inSub-group i under the high speed circumstance is smaller than P₁ ^(g).

Wherein, the maximum cyclic shift N_(CS)=min(du, N_(ZC)−2·du), wherein,du is the distance between a correlation peak and a correlation peakalias thereof, and N_(ZC) is the length of the ZC sequence. The distancebetween the correlation peak and the correlation peak alias thereof is

${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}},}\end{matrix} \right.$

wherein, u is the serial number of the ZC sequence, and m is the minimumpositive integer which makes

$\frac{{m \cdot N_{ZC}} - 1}{u}$

a positive integer.

The present invention not only enables the assignment of the sequencesaccording to the CMs, but also enables the collection of the sequencefragments for use, so that the generation of sequence fragments can beavoided. Meanwhile, the present invention is fully compatible to thefirst and the second re-sequencing methods described in the Backgroundof the Invention, without introducing any extra signaling cost.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrated here provide a further understanding of thepresent invention and form a part of the present application. Theexemplary embodiments and the description thereof are used to explainthe present invention without unduly limiting the scope of the presentinvention, wherein:

FIG. 1 is a schematic diagram of the generation of the sequencefragments in relevant techniques;

FIG. 2 is a flowchart of the method for sequencing the ZC sequences ofthe random access channel according to the embodiments of the presentinvention;

FIG. 3 is a schematic diagram of Step 202 in the method illustrated inFIG. 2;

FIG. 4 is a schematic diagram of Step 204 in the method illustrated inFIG. 2;

FIG. 5 is a schematic diagram of Step 206 in the method illustrated inFIG. 2 (in view of the cubic metric);

FIG. 6 is a schematic diagram of Step 206 in the method illustrated inFIG. 2 (in view of the maximum cyclic shift supported by the ZCsequences); and

FIG. 7 is a block diagram of the device for sequencing the ZC sequencesof the random access channel according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The embodiments of the present invention will be described hereinafterin detail in conjunction with the drawings thereof.

The method for sequencing the ZC sequences of the random access channelaccording to an embodiment of the present invention is described withreference to FIG. 2. As shown in FIG. 2, the method for sequencing theZC sequences comprises the following steps:

Step 202, the ZC sequences are divided into a plurality of groupsaccording to the cubic metrics of the ZC sequences. Specifically, thereare various principles for the group division. For example, the CM ofdata modulated using Quadrature Phase Shift Keying (QPSK for short) is1.2 dB, and this value can be used as a threshold to divide the ZCsequences into two groups: the CMs of the ZC sequences in the firstgroup is smaller than or equal to 1.2 dB; and the CMs of the ZCsequences in the second group is larger than 1.2 dB. Wherein, thefollowing method can be used to carry out this step: sequencing thecubic metrics of the ZC sequences in the increasing order; and dividingthe sequencing result into two groups using the cubic metric (1.2 dB) ofQPSK as a threshold.

Step 204, the ZC sequences are sequenced, according to the maximumcyclic shift supported by the ZC sequences under a high speedcircumstance, within each group to form a plurality of sub-groups. Thesequencing process may be performed in the increasing order or in thedecreasing order, and the adjacent groups (the groups obtained throughStep 202) shall be sequenced in different orders. Moreover, thesequencing process needs to be performed according to a certaingranularity. The granularity of the cyclic shift of Group g is P^(g)={P₁^(g), P₂ ^(g), . . . , P_(s) ^(g)}, and P_(i) ^(g)<P_(i+1) ^(g), thus,(1) the sequencing performed in the increasing order means: when 1<i<s,the maximum cyclic shift supported by each sequence in Sub-group i underthe high speed circumstance is smaller than P_(i+1) ^(g), and largerthan or equal to P_(i) ^(g), when i=1, the maximum cyclic shiftsupported by each sequence in Sub-group i under the high speedcircumstance is smaller than P₁ ^(g), when i=s, the maximum cyclic shiftsupported by each sequence in Sub-group i under the high speedcircumstance is larger than or equal to P_(s) ^(g); (2) the sequencingperformed in the decreasing order means: when 1<i<s, the maximum cyclicshift supported by each sequence in Sub-group i under the high speedcircumstance is smaller than P_(s−i+2) ^(g) and larger than or equal toP_(s−i+1) ^(g), when i=1, the maximum cyclic shift supported by eachsequence in Sub-group i under the high speed circumstance is larger thanor equal to P_(s) ^(g), when i=s, the maximum cyclic shift supported byeach sequence in Sub-group i under the high speed circumstance issmaller than P₁ ^(g).

Step 206, in each sub-group, the sequencing is performed according tothe CM values of the ZC sequences, and the adjacent sub-groups in thesame group are sequenced in different orders, while the sub-groups atthe boundary of the two adjacent groups are sequenced in the same order.

Wherein, since performing the sequencing according to the maximum cellradius supported by the ZC sequences only needs to know the relativerelation between the maximum cell radiuses supported by respective ZCsequences, and since the maximum cell radius supported by each ZCsequence is directly determined by the maximum cyclic shift N_(CS) ofeach ZC sequence, the sequencing process is equivalent to performing asequencing according to N_(CS). Wherein, N_(CS)=min(du, N_(ZC)−2·du), duis the distance between the correlation peak and the correlation peakalias thereof, and N_(ZC) is the length of a ZC sequence. The distancebetween the correlation peak and the correlation peak ali as thereof is

${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}},}\end{matrix} \right.$

wherein, u is the serial number of the ZC sequence, and m is the minimumpositive integer which makes

$\frac{{m \cdot N_{ZC}} - 1}{u}$

a positive integer.

For example, the length N_(ZC) of the ZC sequence is 839, and each cellneeds to generate 64 usable ZCZ sequences. Firstly, the ZC sequences aredivided into two groups according to the CM value (1.2 dB) of the QPSK,wherein, the CM value of the first group is smaller than 1.2 dB, and theCM value of the second group is larger than 1.2 dB (as shown in FIG. 3);secondly, the sequencing is performed according to the granularity {15,18, 22, 26, 32, 38, 46, 55, 68, 82, 100, 128, 158, 202, 237}, andaccording to the maximum cyclic shift supported by the ZC sequencesunder the high speed circumstance, and the sequencing is performed inthe increasing order in the low CM group, while in the decreasing orderin the high CM group, and the ZC sequences are divided into 16sub-groups in each group (as shown in FIG. 4); finally, the sequencingis performed in each sub-group according to the CMs of the sequences,and the adjacent sub-groups are sequenced in different orders (as shownin FIGS. 5 and 6). The sequencing result is shown in table 1

TABLE 1 SG1 SG2 SG3 SG4 SG5 SG6 SG7 SG8 SG9 SG10 SG11 SG12 SG13 SG14SG15 SG16 low cubic metric group 129 56 80 35 808 24 86 744 217 12 228832 687 5 225 3 710 783 759 804 31 815 753 95 622 827 611 7 152 834 614836 140 112 42 766 811 791 761 202 128 816 227 831 144 806 615 820 699727 797 73 28 48 78 637 711 23 612 8 695 33 224 19 719 148 40 693 30 771796 649 697 34 132 823 134 788 618 817 120 691 799 146 809 68 43 190 142805 707 16 705 51 221 22 629 812 74 39 658 122 37 706 792 138 764 220798 210 27 765 800 181 717 802 133 47 701 75 619 41 168 29 661 819 702203 793 143 64 640 740 127 38 671 810 178 20 137 636 46 696 775 199 99712 801 84 703 818 125 721 207 704 57 162 743 147 44 755 136 21 714 118632 135 782 677 96 692 795 105 151 729 660 161 735 176 97 124 52 734 688110 179 678 104 663 742 715 787 746 89 694 201 101 119 166 193 45 93 750145 638 738 720 673 646 794 70 736 709 666 108 681 172 205 63 769 103130 173 731 158 667 634 776 779 61 223 733 631 164 664 633 772 60 778616 106 208 675 175 206 67 2 784 756 655 665 652 723 72 837 55 83 184174 187 116 767 1 824 748 197 668 676 679 76 838 15 91 642 171 163 160763 825 66 648 170 185 186 745 14 773 191 669 654 653 94 53 718 87 639167 737 786 121 752 200 672 102 10 141 670 114 760 90 829 698 169 725 79749 9 149 751 189 754 109 830 690 88 650 85 730 623 107 724 77 165 216732 115 762 674 218 758 194 92 728 621 81 645 747 111 82 195 781 209 757644 58 630 100 647 62 204 739 192 111 635 98 182 69 117 741 657 770 722768 682 54 651 71 157 785 188 59 156 803 680 780 683 36 159 65 211 807198 774 628 32 641 789 154 25 113 50 685 814 726 49 716 821 656 790 12318 183 813 700 828 659 26 139 11 180 822 212 835 177 17 627 4 662 826686 643 13 153 196 6 213 155 833 626 684 215 625 624 214 689 126 150 713708 131 219 620 617 222 613 226 high cubic metric group 609 323 237 509257 346 608 546 242 317 603 484 604 530 367 503 230 516 602 330 582 493231 293 597 522 236 355 235 309 472 336 232 320 600 338 566 500 260 288274 307 303 434 572 265 296 534 607 519 239 501 273 339 579 551 565 532536 405 267 574 543 305 577 334 244 498 584 351 268 284 402 553 356 435302 233 466 262 505 595 341 255 488 571 555 437 286 483 404 537 606 373587 359 243 499 254 306 563 471 383 552 433 280 252 480 596 340 585 533276 368 456 287 406 559 418 544 275 497 245 550 430 253 482 573 560 421295 564 342 594 289 409 586 357 266 279 416 454 561 301 588 439 398 583510 578 419 423 385 278 538 251 400 441 256 329 261 420 426 292 589 366412 461 549 263 240 413 547 250 473 427 378 290 576 599 428 291 246 401467 465 535 258 411 548 593 438 372 374 304 581 463 381 417 468 557 415308 610 376 458 422 371 282 424 531 229 444 399 248 408 436 569 358 395440 591 431 403 270 481 283 380 445 464 396 598 316 556 459 394 375 443241 523 285 442 393 249 447 554 397 446 590 392 379 470 370 269 448 460369 469 570 391 449 462 365 238 457 390 377 474 601 382 363 429 300 605389 476 410 539 234 450 455 407 299 294 384 432 540 545 451 281 475 542388 558 364 297 386 425 362 528 453 414 477 311 478 592 541 344 361 247298 495 452 562 527 345 387 277 312 494 360 568 313 318 479 271 526 521529 272 525 331 310 567 314 508 485 264 353 514 354 575 486 325 511 580487 321 328 259 352 518 524 343 315 496 337 512 502 327 349 350 490 489504 326 335 513 515 319 324 520 332 507 506 333 491 348 492 347 517 322

After the above sequencing process is completed, the mapping relationbetween the sequence indices and the serial numbers of the ZC sequencescan be obtained. As to a practical system, the mapping relation can bestored in the memories of a mobile phone and a base station. After thebase station informs, via the BCH channel, the mobile phone the sequenceindex, the mobile phone can find the serial number of the ZC sequencecorresponding to the index according to the mapping relation, and thengenerate usable ZCZ sequences according to the step length of cyclicshift and the cyclic shift limitation rule. If the number of the ZCZsequences is smaller than 64, the mobile phone increments the index, andcontinuously generates ZCZ sequences using the next ZC sequence untilthe total number of the ZCZ sequences reaches 64. Finally, the mobilephone randomly selects one sequence from all the generated ZCZ sequencesas a preamble to be sent.

The device for sequencing the ZC sequences of the random access channelaccording to an embodiment of the present invention is described withreference to FIG. 7. As shown in FIG. 7, the device for sequencing theZC sequences of the to random access channel comprises: a first groupdividing unit 702, configured to divide Nq ZC sequences into a pluralityof groups according to the cubic metrics of the ZC sequences of therandom access channel; a second group dividing unit 704, configured tosequence the ZC sequences within each group to form some sub-groupsaccording to the maximum cyclic shift supported by the ZC sequencesunder high speed circumstance; and a sequencing unit 706, configured tosequence the ZC sequences in each of the plurality of sub-groupsaccording to the cubic metrics of the ZC sequences, wherein, theadjacent sub-groups in the same group are sequenced in different orders,while the sub-groups at the boundary of the two adjacent groups aresequenced in the same order.

Wherein, the first group dividing unit divides the Nq ZC sequences intoG groups, wherein, 1≦G≦Nq, the relation between the serial number ofeach group and the cubic metrics of the ZC sequences in each group is:the cubic metrics of the ZC sequences in Group i is smaller than thecubic metrics of the ZC sequences in Group i+1, or the cubic metrics ofthe ZC sequences in Group i is larger than the cubic metrics of the ZCsequences in Group i+1. Specifically, the first group dividing unitdivides the Nq ZC sequences into two groups using the cubic metrics ofQuadrature Phase Shift Keying as a threshold.

Wherein, the second group dividing unit divides the ZC sequences in eachsub-group into a plurality of sub-groups according to one of thefollowing principles: the maximum cyclic shift supported by the ZCsequences in Sub-group i under the high speed circumstance is smallerthan the maximum cyclic shift supported by the ZC sequences in Sub-groupi+1 under the high speed circumstance, the maximum cyclic shiftsupported by the ZC sequences in Sub-group i under the high speedcircumstance is larger than the maximum cyclic shift supported by the ZCsequences in Sub-group 1+1 under the high speed circumstance, wherein,the second group dividing unit applies different principles to thesub-groups in adjacent groups.

Wherein, the sequencing process of the second group dividing unit may beperformed in the increasing order or in the decreasing order, and theadjacent groups should be sequenced in different orders.

Wherein, the sequencing process of the second group dividing unit needsto be performed according to a certain granularity. The granularity ofthe cyclic shift of Group g is P^(g)={P₁ ^(g), P₂ ^(g), . . . , P_(s)^(g)} and P_(i) ^(g)<P_(i+1) ^(g), thus, (1) the sequencing performed inthe increasing order means: when 1<i<s, the maximum cyclic shiftsupported by each sequence in Sub-group i under the high speedcircumstance is smaller than P_(i+1) ^(g), and larger than or equal toP_(i) ^(g), when i=1, the maximum cyclic shift supported by eachsequence in Sub-group i under the high speed circumstance is smallerthan P₁ ^(g), when i=s, the maximum cyclic shift supported by eachsequence in Sub-group i under the high speed circumstance is larger thanor equal to P_(s) ^(g); (2) the sequencing performed in the decreasingorder means: when 1<i<s, the maximum cyclic shift supported by eachsequence in Sub-group i under the high speed circumstance is smallerthan P_(s−i+2) ^(g), and larger than or equal to P_(s−i+1) ^(g), wheni=1, the maximum cyclic shift supported by each sequence in Sub-group iunder the high speed circumstance is larger than or equal to P_(s) ^(g),when i=s, the maximum cyclic shift supported by each sequence inSub-group i under the high speed circumstance is smaller than P₁ ^(g).

Wherein, the maximum cyclic shift of the ZC sequences isN_(CS)=min(du,N_(ZC)−2·du) wherein, du is the distance between acorrelation peak and a correlation peak alias thereof, and N_(ZC) is thelength of the ZC sequence. The distance between the correlation peak andthe correlation peak alias thereof is

${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}},}\end{matrix} \right.$

wherein, u is the serial number of the ZC sequence, and m is the minimumpositive integer which makes

$\frac{{m \cdot N_{ZC}} - 1}{u}$

a positive integer. Wherein, the sequence dividing unit can divide aplurality of ZC sequences, being sequenced after the first sequencing,into two groups according to the cubic metrics of Quadrature Phase ShiftKeying.

The descriptions above are only preferable embodiments of the presentinvention, which are not used to restrict the present invention. Forthose skilled in to the art, the present invention may have variouschanges and variations. Any amendments, equivalent substitutions,improvements etc. within the spirit and principle of the presentinvention are all included in the scope of the claims of the presentinvention.

1. A method for sequencing the ZC sequences of the random accesschannel, comprising the following steps: Step 202, dividing Nq ZCsequences into a plurality of groups according to the cubic metrics ofthe ZC sequences; Step 204, sequencing the ZC sequences, according tothe maximum cyclic shift supported by the ZC sequences under a highspeed circumstance, within each group to form a plurality of sub-groups;and Step 206, sequencing the ZC sequences within each of said pluralityof sub-groups according to the cubic metrics of the ZC sequences,wherein, the adjacent sub-groups in the same group are sequenced indifferent orders, while the sub-groups at the boundary of the twoadjacent groups are sequenced in the same order.
 2. The method forsequencing the ZC sequences of the random access channel according toclaim 1, wherein, said Nq ZC sequences are divided into G groups,wherein, 1≦G≦Nq, the relation between the serial number of each of saidplurality of groups and the cubic metrics of the ZC sequences in each ofsaid plurality of groups is: the cubic metrics of the ZC sequences inGroup i are smaller than the cubic metrics of the ZC sequences in Groupi+1, or the cubic metrics of the ZC sequences in Group i are larger thanthe cubic metrics of the ZC sequences in Group i+1.
 3. The method forsequencing the ZC sequences of the random access channel according toclaim 1, wherein, said Nq ZC sequences are divided into two groupsaccording to the cubic metrics of Quadrature Phase Shift Keying.
 4. Themethod for sequencing the ZC sequences of the random access channelaccording to claim 1, wherein, in Step 202, firstly, said Nq ZCsequences are sequenced, in the decreasing order or in the increasingorder, according to the cubic metrics of the ZC sequences, and then, thesequencing result is divided into a plurality of groups according to oneor more cyclic shift thresholds.
 5. The method for sequencing the ZCsequences of the random access channel according to claim 1, wherein, inStep 204, the sequencing is performed in the increasing order or in thedecreasing order, and the adjacent groups are sequenced in differentorders.
 6. The method for sequencing the ZC sequences of the randomaccess channel according to claim 1, wherein, in Step 204, thesequencing is performed according to a certain granularity.
 7. Themethod for sequencing the ZC sequences of the random access channelaccording to claim 5, wherein, the granularity of the cyclic shift ofGroup g is P^(g)={P₁ ^(g), P₂ ^(g), . . . , P_(s) ^(g)}, and P_(i)^(g)<P_(i+1) ^(g), and the sequencing performed in the increasing ordermeans: when 1<i<s, the maximum cyclic shift supported by each ZCsequence in Sub-group i under the high speed circumstance is smallerthan P_(i+1) ^(g), and larger than or equal to P_(i) ^(g), when i=1, themaximum cyclic shift supported by each ZC sequence in Sub-group i underthe high speed circumstance is smaller than P₁ ^(g), when i=s, themaximum cyclic shift supported by each ZC sequence in Sub-group i underthe high speed circumstance is larger than or equal to P_(s) ^(g), andthe sequencing performed in the decreasing order means: when 1<i<s, themaximum cyclic shift supported by each ZC sequence in Sub-group i underthe high speed circumstance is smaller than P_(s−i+2) ^(g), and largerthan or equal to P_(s−i+1) ^(g), when i=1, the maximum cyclic shiftsupported by each ZC sequence in Sub-group i under the high speedcircumstance is larger than or equal to P_(s) ^(g), when i=s, themaximum cyclic shift supported by each ZC sequence in Sub-group i underthe high-speed circumstance is smaller than P₁ ^(g).
 8. The method forsequencing the ZC sequences of the random access channel according toclaim 1, wherein, said maximum cyclic shift N_(CS)=min(du,N_(ZC)−2·du),wherein, du is the distance between a correlation peak and a correlationpeak alias thereof, and N_(ZC) is the length of said ZC sequence.
 9. Themethod for sequencing the ZC sequences of the random access channelaccording to claim 8, wherein, said distance between the correlationpeak and the correlation peak alias thereof is${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}},}\end{matrix} \right.$ wherein, u is the serial number of said ZCsequence, and m is the minimum positive integer which makes$\frac{{m \cdot N_{ZC}} - 1}{u}$ a positive integer.
 10. A device forsequencing the ZC sequences of the random access channel comprising: afirst group dividing unit, configured to divide Ng ZC sequences into aplurality of groups according to the cubic metrics of the ZC sequencesof the random access channel; a second group dividing unit, configuredto sequence the ZC sequences within each group to form a plurality ofsub-groups, according to the maximum cyclic shift supported by the ZCsequences under a high speed circumstance; and a sequencing unit,configured to sequence the ZC sequences in each of said plurality ofsub-groups according to the cubic metrics of the ZC sequences, wherein,the adjacent sub-groups in the same group are sequenced in differentorders, while the sub-groups at the boundary of the two adjacent groupsare sequenced in the same order.
 11. The device for sequencing the ZCsequences of the random access channel according to claim 10, wherein,said first group dividing unit divides said Nq ZC sequences into Ggroups, wherein, 1≦G≦Nq, the relation between the serial number of eachof said plurality of groups and the cubic metrics of the ZC sequences ineach of said plurality of groups is: the cubic metrics of the ZCsequences in Group i are smaller than the cubic metrics of the ZCsequences in Group i+1, or the cubic metrics of the ZC sequences inGroup i are larger than the cubic metrics of the ZC sequences in Groupi+1.
 12. The device for sequencing the ZC sequences of the random accesschannel according to claim 10, wherein, said first group dividing unitdivides said Nq ZC sequences into two groups using the cubic metrics ofQuadrature Phase Shift Keying as a threshold.
 13. The device forsequencing the ZC sequences of the random access channel according toclaim 10, wherein, said second group dividing unit performs thesequencing of the ZC sequences in each group in the increasing order orin the decreasing order, and the adjacent groups are sequenced indifferent orders.
 14. The device for sequencing the ZC sequences of therandom access channel according to claim 10, wherein, said second groupdividing unit performs the sequencing according to a certaingranularity.
 15. The device for sequencing the ZC sequences of therandom access channel according to claim 13, wherein, the granularity ofthe cyclic shift of Group g is P^(g)={P₁ ^(g), P₂ ^(g), . . . , P_(s)^(g)}, and P_(i) ^(g)<P_(i+1) ^(g) performing the sequencing in theincreasing order means: when 1<i<s, the maximum cyclic shift supportedby each sequence in Sub-group i under the high speed circumstance issmaller than P_(i+1) ^(g), and larger than or equal to P_(i) ^(g), wheni=1, the maximum cyclic shift supported by each sequence in Sub-group iunder the high speed circumstance is smaller than P_(i) ^(g), when i=s,the maximum cyclic shift supported by each sequence in Sub-group i underthe high speed circumstance is larger than or equal to P_(s) ^(g),performing the sequencing in the decreasing order means: when 1<i<s, themaximum cyclic shift supported by each sequence in Sub-group i under thehigh speed circumstance is smaller than P_(s−i+2) ^(g), and larger thanor equal to P_(s−i+1) ^(g), when i=1, the maximum cyclic shift supportedby each sequence in Sub-group i under the high speed circumstance islarger than or equal to P_(s) ^(g), when i=s, the maximum cyclic shiftsupported by each sequence in Sub-group i under the high speedcircumstance is smaller than P₁ ^(g).
 16. The device for sequencing theZC sequences of the random access channel according to claim 10,wherein, said maximum cyclic shift N_(CS)=min(du, N_(ZC)−2·du), wherein,du is the distance between a correlation peak and a correlation peakalias thereof, and N_(ZC) is the length of said ZC sequence.
 17. Thedevice for sequencing the ZC sequences of the random access channelaccording to claim 16, wherein, said distance between the correlationpeak and the correlation peak alias thereof is${du} = \left\{ \begin{matrix}{\frac{{m \cdot N_{ZC}} - 1}{u},} & {{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} \leq {{floor}\left( {N/2} \right)}} \\{{N_{ZC} - \frac{{m \cdot N_{ZC}} - 1}{u}},} & {{{{when}\mspace{14mu} \frac{{m \cdot N_{ZC}} - 1}{u}} > {{floor}\left( {N/2} \right)}},}\end{matrix} \right.$ wherein, u is the serial number of said ZCsequence, and m is the minimum positive integer which makes$\frac{{m \cdot N_{ZC}} - 1}{u}$ a positive integer.
 18. The method forsequencing the ZC sequences of the random access channel according toclaim 2, wherein, said maximum cyclic shift N_(CS)=min(du, N_(ZC)−2·du),wherein, du is the distance between a correlation peak and a correlationpeak alias thereof, and N_(ZC) is the length of said ZC sequence. 19.The method for sequencing the ZC sequences of the random access channelaccording to claim 3, wherein, said maximum cyclic shift N_(CS)=min(du,N_(ZC)−2·du), wherein, du is the distance between a correlation peakand a correlation peak alias thereof, and N_(ZC) is the length of saidZC sequence.
 20. The device for sequencing the ZC sequences of therandom access channel according to claim 11, wherein, said maximumcyclic shift N_(CS)=min(du,N_(ZC)−2·du), wherein, du is the distancebetween a correlation peak and a correlation peak alias thereof, andN_(ZC) is the length of said ZC sequence.